1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
#ifndef UTIL_STREAM_CHAIN__
#define UTIL_STREAM_CHAIN__
#include "util/stream/block.hh"
#include "util/stream/config.hh"
#include "util/stream/multi_progress.hh"
#include "util/scoped.hh"
#include <boost/ptr_container/ptr_vector.hpp>
#include <boost/thread/thread.hpp>
#include <cstddef>
#include <assert.h>
namespace util {
template <class T> class PCQueue;
namespace stream {
class ChainConfigException : public Exception {
public:
ChainConfigException() throw();
~ChainConfigException() throw();
};
class Chain;
// Specifies position in chain for Link constructor.
class ChainPosition {
public:
const Chain &GetChain() const { return *chain_; }
private:
friend class Chain;
friend class Link;
ChainPosition(PCQueue<Block> &in, PCQueue<Block> &out, Chain *chain, MultiProgress &progress)
: in_(&in), out_(&out), chain_(chain), progress_(progress.Add()) {}
PCQueue<Block> *in_, *out_;
Chain *chain_;
WorkerProgress progress_;
};
// Position is usually ChainPosition but if there are multiple streams involved, this can be ChainPositions.
class Thread {
public:
template <class Position, class Worker> Thread(const Position &position, const Worker &worker)
: thread_(boost::ref(*this), position, worker) {}
~Thread();
template <class Position, class Worker> void operator()(const Position &position, Worker &worker) {
try {
worker.Run(position);
} catch (const std::exception &e) {
UnhandledException(e);
}
}
private:
void UnhandledException(const std::exception &e);
boost::thread thread_;
};
class Recycler {
public:
void Run(const ChainPosition &position);
};
extern const Recycler kRecycle;
class WriteAndRecycle;
class Chain {
private:
template <class T, void (T::*ptr)(const ChainPosition &) = &T::Run> struct CheckForRun {
typedef Chain type;
};
public:
explicit Chain(const ChainConfig &config);
~Chain();
void ActivateProgress() {
assert(!Running());
progress_.Activate();
}
void SetProgressTarget(uint64_t target) {
progress_.SetTarget(target);
}
std::size_t EntrySize() const {
return config_.entry_size;
}
std::size_t BlockSize() const {
return block_size_;
}
// Two ways to add to the chain: Add() or operator>>.
ChainPosition Add();
// This is for adding threaded workers with a Run method.
template <class Worker> typename CheckForRun<Worker>::type &operator>>(const Worker &worker) {
assert(!complete_called_);
threads_.push_back(new Thread(Add(), worker));
return *this;
}
// Avoid copying the worker.
template <class Worker> typename CheckForRun<Worker>::type &operator>>(const boost::reference_wrapper<Worker> &worker) {
assert(!complete_called_);
threads_.push_back(new Thread(Add(), worker));
return *this;
}
// Note that Link and Stream also define operator>> outside this class.
// To complete the loop, call CompleteLoop(), >> kRecycle, or the destructor.
void CompleteLoop() {
threads_.push_back(new Thread(Complete(), kRecycle));
}
Chain &operator>>(const Recycler &recycle) {
CompleteLoop();
return *this;
}
Chain &operator>>(const WriteAndRecycle &writer);
// Chains are reusable. Call Wait to wait for everything to finish and free memory.
void Wait(bool release_memory = true);
// Waits for the current chain to complete (if any) then starts again.
void Start();
bool Running() const { return !queues_.empty(); }
private:
ChainPosition Complete();
ChainConfig config_;
std::size_t block_size_;
scoped_malloc memory_;
boost::ptr_vector<PCQueue<Block> > queues_;
bool complete_called_;
boost::ptr_vector<Thread> threads_;
MultiProgress progress_;
};
// Create the link in the worker thread using the position token.
class Link {
public:
// Either default construct and Init or just construct all at once.
Link();
void Init(const ChainPosition &position);
explicit Link(const ChainPosition &position);
~Link();
Block &operator*() { return current_; }
const Block &operator*() const { return current_; }
Block *operator->() { return ¤t_; }
const Block *operator->() const { return ¤t_; }
Link &operator++();
operator bool() const { return current_; }
void Poison();
private:
Block current_;
PCQueue<Block> *in_, *out_;
bool poisoned_;
WorkerProgress progress_;
};
inline Chain &operator>>(Chain &chain, Link &link) {
link.Init(chain.Add());
return chain;
}
} // namespace stream
} // namespace util
#endif // UTIL_STREAM_CHAIN__
|
